The present subject matter relates to a heliostat system and a method of using the heliostat system. In particular, the present subject matter is directed to a heliostat system with reflective surfaces of a reduced size, each reflective surface having an individual actuator associated therewith in order to facilitate movement of the respective reflective surface.
In general, solar power generation involves the conversion of solar energy to electrical energy. This can be implemented through different technologies such as photovoltaics or heating a transfer fluid to produce vapor or hot gases to run a turbine generator, for example. In some solar power generation systems one or more heliostats may be used to reflect solar radiation onto a collection point to enhance overall efficiency. Typically, each heliostat is controlled to track the sun and maintain reflection of the solar radiation on the collection point throughout the day. The solar radiation received at the collection point may be converted using any known technology. Typical conversion methods include thermal conversion using solar-generated steam or other working fluids, or direct conversion to electricity using photovoltaic cells.
On larger scales, solar power generation from concentrated sunlight may employ fields of multiple heliostats for solar energy collection. Each heliostat typically requires power distribution in order to drive the motor positioners and data communication in order to facilitate sun tracking control. In a conventional heliostat field, the complete heliostat is moved according to the positioners, thus require relatively large amounts of energy since the heliostat is generally very heavy and large motors are needed to move them.
Furthermore, costs associated with laying cables to each heliostat over a large area are significant and site specific. These costs include trenching, conduit, wire, wire installation, and wire maintenance. Because solar power facilities extend over very large areas to capture more radiation, such trenching, conduit and wire runs are very long and thus expensive. Additionally, because each solar power facility must be designed for site-specific conditions, standardized site or cabling designs have not proven effective at reducing costs. Also, because soil conditions are often difficult to assess for an entire site (e.g., spanning many tens or hundreds of acres), unanticipated soil mechanics can quickly disrupt cost and schedule for a project. Finally, because solar power facilities are designed to operate over 30 or more years, infrastructure maintenance is also a significant economic consideration. Such geographically dispersed infrastructure is expensive to maintain, made worse when buried wiring is employed under the standard approach.
For a single large solar power plant (e.g., generating approximately 100 MW) the cost of building and maintaining this infrastructure would be in the millions of dollars. The solar power generation industry is revisiting heliostat-based architectures for cost-effective large-scale deployment. If heliostat-based architectures become the solution of choice, the annual savings from this subject matter could be very significant.